In recent years, treadmill devices have become increasingly popular to afford users the opportunity to exercise by running or walking indoors. Such devices ordinarily include a powered track, or tread, which is driven at selectively variable speeds in accordance with the speed at which the user wishes to run or walk. While treadmill devices had been available for use in health clubs and the like for some time, the versatility of use offered by such devices has made them increasingly popular for home use. As such, it is important that the devices not only be durably constructed, but also relatively economical if they are to be affordable for home use.
In this regard, one feature of such devices which enhances their versatile use is the provision of an arrangement for selectively adjusting the inclination of the treadmill. Such arrangements permit the user to vary the level of exertion during use by simulating running or walking on "level terrain" (with a low level of inclination), or "uphill" (with a high angle of inclination).
The highest degree of versatility and convenience is offered when such inclination arrangements are powered, permitting a user to effect adjustment while standing on the treadmill. As will be appreciated, however, such powered arrangements are subjected to very high loading, including impact loading when a user runs on the treadmill.
While past constructions have used ball-screw drive mechanisms for effecting powered inclination adjustment, such arrangements are not particularly economical, thereby detracting from the affordability of such treadmill devices. The present invention contemplates an inclination drive mechanism for a treadmill which is specifically configured for economical use, while providing the load-bearing characteristics necessary for reliable operation of such arrangements.